As a preparation to zcm 2017 I started to upgrade my 3 primary server to windows 2012 R2.

I started with the first one. The windows upgrade works fast and after the upgrade I'm unable to login to the server.

Everything looking fine, even the zen services are running and the zcm console know that the server is with a new OS.

I looked on event log and find an error about LogonUI.exe and ZenCredentialProvider.dll.

I have found here this :

I added the key to the server and reboot couple of times, and still same problem.

First, what should I do to logon to the server ?
and how should I make the other 2 in-place upgrades ?